Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, a generator, a gearbox, a nacelle, and a rotor having a rotatable hub with one or more rotor blades. The rotor blades capture kinetic energy of wind using known airfoil principles. The rotor blades transmit the kinetic energy in the form of rotational energy so as to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid.
Each rotor blade of a wind turbine typically includes a suction side shell and a pressure side shell formed using molding processes that are subsequently bonded together via adhesives at bond lines along the leading and trailing edges of the blade. The pressure and suction side shells are relatively lightweight and have structural properties (e.g., stiffness, buckling resistance and strength) that are not configured to withstand the bending moments and other loads exerted on the rotor blade during operation. Thus, to increase the stiffness, buckling resistance and strength of the rotor blade, the shells are typically reinforced using one or more structural components (e.g. opposed spar caps with a shear web configured therebetween) that engage the pressure and suction side inner surfaces of the shell halves. The spar caps are typically constructed of various materials, including but not limited to, fiber-reinforced laminate composites including a thermoset resin. The shells of the rotor blade are generally built around the spar caps by stacking layers of fiber fabrics in a shell mold. The layers are then typically infused together, e.g. with a thermoset resin.
In general, the methods used to manufacture the rotor blades and/or structural components thereof can be difficult to control, defect prone, and/or highly labor intensive due to handling of the dry fabrics and the challenges of infusing large laminated structures. Moreover, as rotor blades continue to increase in size, conventional manufacturing methods continue to increase in complexity as the blade halves are typically manufactured using opposing mold halves that must be large enough to accommodate the entire length of the rotor blade. As such, joining the large blade halves can be highly labor intensive and more susceptible to defects.
One known strategy for reducing the complexity and costs associated with pre-forming, transporting, and erecting wind turbines having rotor blades of increasing sizes is to manufacture the rotor blades in blade segments. The blade segments may then be assembled to form the rotor blade. However, known joint designs for connecting blade segments together typically have a variety of disadvantages. For example, many known joint designs utilize mechanical fasteners, such as bolts and nuts, to secure blade segments together. However, the fastening components used in such bolted joint designs are typically quite heavy, thereby significantly increasing the overall weight of the rotor blade. Additionally, it is known to create a scarfed joint between two blade segments in which the joint ends of the segments are machined to form a scarfed or tapered profile across which a hand laminate is subsequently applied to join the segments together. However, such scarfing methodologies are often very time consuming and quite complex.
Accordingly, an improved joint connection for joining adjacent blade segments of a segmented blade that addresses one or more of the issues described above would be welcomed in the technology.